number_of_features(x)

## S4 method for signature 'ConservationProblem'
number_of_features(x)

## S4 method for signature 'OptimizationProblem'
number_of_features(x)

## S4 method for signature 'ZonesRaster'
number_of_features(x)

## S4 method for signature 'ZonesCharacter'
number_of_features(x)

# load data
data(sim_pu_raster, sim_features)

# create problem
p <- problem(sim_pu_raster, sim_features) %>%
     add_min_set_objective() %>%
     add_relative_targets(0.2) %>%
     add_binary_decisions()

# print number of features
print(number_of_features(p))